Do I have a case for a misdiagnosis that led me to have brain surgery and lost 100% of my hearing in that ear?

You may have a claim for medical malpractice, however, you should be aware that in Ohio you only have 1 year from the date you knew or should have known of the malpractice. You should get copies of both MRIs and then schedule an appointment with an attorney as soon as possible if you are going to try and pursue a claim.

I doubt if a doctor will testify about the 09 and 13 diagnosis but this is a medical matter not a legal matter. How would a doctor know how long the tumor was there? Ask him?

You have a medical malpractice claim, but there are serious problems with it. First, the attorney of the doctor's insurance company will argue that your claim is barred by the statute of limitations. In New York, a medical malpractice claim must be brought within 30 months from a) the date of the malpractice, or b) the last day of continuous treatment, or c) from the date when the malpractice was discovered or should have been reasonably discovered. Your only hope is the c). The defense will argue that, since you did not go to an ENT doctor for 4 years despite continued symptoms, the delay in discovery was caused by your inaction and was not reasonable. The court might agree with them. If the court lets you proceed with your claim, the second problem will come to the fore: the burden of proof. To prevail in this case, you will have to show that the tumor was, in fact, there when the doctor failed to find it in 2009. Your attorney will call expert witnesses who will say that is is more likely than not that the tumor was there to be found; the defense attorneys will call their own expert witnesses who will say there is no way to be sure about it. The defense attorney will ask your expert witness whether there is any way of knowing whether the tumor, if it were there, was large enough to be found - and there is no honest oncologist, ENT, or any other medical specialist who will not admit that, in this case, no one can be certain. So, I would say that your odds of winning on this claim are rather small. You might still try. If you win on the issue of the statute of limitations, and the court will allow the case to proceed, the insurance company will, most likely, offer you some money as a settlement.

In Alabama, you may be too late, depending on the facts.

Two problems: one is statute of limitations. In NY, its 30 months from the date of the last treatment of the condition which is the subject of the malpractice. The second is whether the first EMT followed accepted standards of practice. You would have to prove, with expert testimony, that the first EMT failed to follow accepted standards. You might be able to succeed on both, but it won't be easy.

Why did you wait 4 years to go back to a doctor? You need to find a doctor who will testify for you. However your delay will add problems to your case.

Ask your 2nd ENT.